So... Bitcoin,
There are two ways to send money. If the recipient is online, you can enter their IP address and it will connect, get a new public key and send the transaction with comments. ...
Then, Core screwed this.

@ProfFaustus

BTC CNCT

Generating RSA Private and Public Keys

Hackernoon

Private and Public Keys in Cryptocurrencies

/r/CryptoMarkets

BTC

Bobby Lee Shares How a Bitcoin Public Key For Fundraising Works Via QR Code

Bitcoin Exchange Guide

BTC

BTC

Bitcoin [BTC] account public key is a great way to raise money, says Bobby Lee

AMBCrypto

BTC

BitMEX Research has set up a lightning network node:
Public Key: 0287416bd553ff2630ff54640e3a7e4230d632387039313bf5a24d7df2006e13c2
https://t.co/KEyOfBwiV9
Feel free to open a channel to our node
Deposits & withdrawals are still a long way off, but at least this is a start https://t.co/FkFU1gvYnm

@BitMEXResearch

BTX

Bitcore BTX - Core 0.15.1.0 released - full new public key support

/r/CryptoMarkets

BTX

BTX

Important update regarding the Bitcore public key format

/r/CryptoMarkets

BTX

04:42 26 Apr

CoinDesk

How Crypto Markets Are Reacting to the Tether-Bitfinex Allegations

The cryptocurrency markets endured a loss of as much as $10 billion around 21:00 UTC on Thursday, following allegations that the Bitfinex exchange covered up an $850 million shortfall using the U.S. dollar-pegged Tether (USDT) stablecoin. The New York Attorney General’s office ...